摸大红支持购物车多选一起结账

下单支持多商品行快照与一次支付；支付后整单复制文案，前台提供购物车加购与结账。

backend/internal/modules/mohong/presenter.go

@@ -2,6 +2,7 @@ package mohong
 
 import (
 	"encoding/json"
+	"fmt"
 	"strings"
 
 	"hfb_sys/backend/internal/model"
@@ -42,7 +43,40 @@ func toProductDTOWithCategory(row model.MohongProduct, categoryName string, incl
 	return dto
 }
 
-func toOrderDTO(row model.MohongOrder, snap productSnapshot, buyerNickname, buyerPhone string, includeAdmin bool) OrderDTO {
+func toOrderDTO(row model.MohongOrder, snap productSnapshot, items []orderItemSnapshot, buyerNickname, buyerPhone string, includeAdmin bool) OrderDTO {
+	if len(items) == 0 {
+		items = decodeOrderItems(row)
+	}
+	title := snap.Title
+	cover := snap.CoverURL
+	unit := snap.Unit
+	if title == "" && len(items) > 0 {
+		title = items[0].Title
+	}
+	if cover == "" && len(items) > 0 {
+		cover = items[0].CoverURL
+	}
+	if unit == "" && len(items) > 0 {
+		unit = items[0].Unit
+	}
+	if len(items) > 1 && title != "" {
+		title = fmt.Sprintf("%s 等%d种", title, len(items))
+	}
+	itemDTOs := make([]OrderItemDTO, 0, len(items))
+	for _, item := range items {
+		lineAmount := item.PriceCent * int64(item.Quantity)
+		itemDTOs = append(itemDTOs, OrderItemDTO{
+			ProductID:     item.ID,
+			Title:         item.Title,
+			CoverURL:      item.CoverURL,
+			Unit:          item.Unit,
+			Quantity:      item.Quantity,
+			UnitPriceCent: item.PriceCent,
+			UnitPrice:     money.Format(item.PriceCent),
+			AmountCent:    lineAmount,
+			Amount:        money.Format(lineAmount),
+		})
+	}
 	dto := OrderDTO{
 		ID:                row.ID,
 		OrderNo:           row.OrderNo,
@@ -54,9 +88,10 @@ func toOrderDTO(row model.MohongOrder, snap productSnapshot, buyerNickname, buye
 		AmountCent:        row.AmountCent,
 		Amount:            money.Format(row.AmountCent),
 		Status:            row.Status,
-		ProductTitle:      snap.Title,
-		ProductCoverURL:   snap.CoverURL,
-		ProductUnit:       snap.Unit,
+		ProductTitle:      title,
+		ProductCoverURL:   cover,
+		ProductUnit:       unit,
+		Items:             itemDTOs,
 		QrcodeURLSnapshot: row.QrcodeURLSnapshot,
 		CopyText:          row.CopyText,
 		CancelReason:      row.CancelReason,